Boyle's Law of Gases, actually more accurately, the ideal gas law establishes the relationship between amount (in number of molecules), temperature, volume and pressure of a gas.

Given a fixed amount of gas (in number of molecules), decrease the volume and the pressure and temperature will rise. The more you decrease the volume the greater the temperature and pressure. Yes, a gas heats up as it is pressurized. This added heat and pressure results in an increase in combustion pressure and temperature causing a higher compression engine to operate with greater power and more heat.

You may have said it already, but which lights did you put on your crash bars? While riding a twisty mountain road in dense fog this weekend it occurred to me that if my headlight winked out I'd likely run off the road--a backup would be a good idea.

I put some Gold Valves in (well, actually somebody else did it for me at Datchew's Tech Day while I stood there with my hands in my pockets). They really make a difference. I can't feel any brake dive under normal circumstances, just a little when I crank down on the lever. I tried them on my 'bump test'--I hit a 6" curb at a steady 10 mph. I've hit the same curb many times so I know how it used to feel. I got prepared for the hit but nothing happened. The Gold Valves made it seem like I ran over a nickel. So far I can't see a downside. I think you'll really like them.

They're PIAA 510 driving pattern (not fog) with "super white" bulbs in them. They're available on amazon for $145. Just be sure to get the driving pattern as I've heard that the fog pattern is so diffused that it's relatively useless. I'd definitely have no qualms at all about using these as my primary headlight. At 55 watts each they throw a healthy amount of light. I have them wired up to my high beam switch via their own relay as my primary headlight doesn't have a high beam. My "highbeam" is my regular headlight + PIAAs.

i'm familiar. it's just not every motorcycle forum where you hear gas laws quoted.

the mage comment was based on an extrapolation that if you're quoting gas laws during a motorcycle discussion that you're probably also a D&D enthusiast.

Quote:

Originally Posted by Airhead Wrangler

Say what?

I always assumed low comp = less power, less heat.

Boyle's Law of Gases, actually more accurately, the ideal gas law establishes the relationship between amount (in number of molecules), temperature, volume and pressure of a gas.

Given a fixed amount of gas (in number of molecules), decrease the volume and the pressure and temperature will rise. The more you decrease the volume the greater the temperature and pressure. Yes, a gas heats up as it is pressurized. This added heat and pressure results in an increase in combustion pressure and temperature causing a higher compression engine to operate with greater power and more heat.

Just talkin shit and playing on stereotypes, no real offense intended. Sorry if that didn't come across. The last thing I mean to do is offend anyone around here, especially those that have helped me out.

EDIT: I definitely didn't mean to imply that you live in your parents' basement and don't get laid. After reading that again I can see how that could be inferred. Woops. I give up. I'm an ass.

i'm awash in sarcasm. no offense at all.i'd only be offended if i wasn't getting laid and was living in my parent's basement.

Quote:

Originally Posted by Airhead Wrangler

Just talkin shit and playing on stereotypes, no real offense intended. Sorry if that didn't come across. The last thing I mean to do is offend anyone around here, especially those that have helped me out.

This seems contrary to Boyle's Law of Gases, but if anyone cares to explain to me how this is possible I'd love to hear it.

I used to think the same thing - but evidently what really happens is that lower compression isn't as efficient. Instead of the charge being converted to mechanical energy, much more of it is converted to heat. Higher compression will 'extract' more power from the fuel and give better mileage.

As I understand it, increasing your compression ratio will increase your thermal efficiency (ie less waste heat per unit of kinetic energy produced), but in absolute terms it will increase the amount of waste heat produced. Any authorities out there care to dig into their mechanical engineering text books and clear this one up? Anyone up for some D&D in Blake's parents' basement?

I've got Cameron's book on motorcycle performance in my "pannier of holding', gimme a sec, lemme find it.....he says more compression = more heat, in general. He recommends larger radiators on water cooled bikes to overcome that more heat so that you can run more compression. The BMW, with it's singled sided swingarm, is already defying all laws of physics. Perhaps they don't apply on our bikes.

I have progressives and am considering the gold valve mod, but if simply changing the oil is a good enough improvement (as i'm not that hard of a rider) then I'd rather do that.

Yeah, I figured I might as well establish a baseline before I try to improve on it. Improvement on an untried suspension setup is tough to gauge. That and I was just plain sick of wrenching on my bike instead of riding it. My riding to wrenching ratio has been a little too lopsided lately.

Quote:

Originally Posted by datchew

By the way, I heard that Blake lives in his parents basement and doesn't get laid. Sounds like a vicious rumour , but i'm gonna pass it on.

Yeah, I heard he still wears a retainer and cuts the crust off his sandwiches. Not sure where I heard that, but I'm pretty sure I DID hear that.

just for the record, I do get laid, (occasionally) and I dont live in my parents basement, but occasionally I get laid in my parents basement. Once I even got laid in the basement playing D+D, but I'm sure this is too much info. And here we were discussing gas laws a moment ago, and also for hte record I think you (Dat) should definitely try the fork oil route first.

Also for the record, I have never seen an aircooled bike much over 10:1, and all the 12:1's I know are heavily auxcooled, so I would think the more compression would equal more heat, despite the inefficient burn of low comp.

Looking back, i realize this adds very little, but I like this thread.